1. Field of the Invention
The invention relates to an apparatus for automatically turning over fish fillets from one of their main surfaces to the other, the apparatus comprising means for supplying the fillets to be turned over and means for discharging the fillets when they have been turned over.
In the processing of fish, particularly bulk fish with the aim of gaining fish products appropriate for human nutrition it is conventional practice these days to perform such processing in a mechanical manner, in particular in a fully automatic manner. The most common processing product is in the form of a fish fillet, which is gained by means of fish filleting machines which normally produce single or double fillets including the skin. When fillets are required without skin this may be removed by fillet skinning machines.
For reasons of economy of such treatment it is desirable for example to combine the processing steps in one automatic process by interlinking the necessary single machines or machine units to form one total installation. Such linking is, however, only possible if fillets which leave the filleting machine normally lying on their meat side are turned over, since the usual, proved and reliable skinning systems require a supplying of the fillets with their skin facing downwardly.
2. Prior Art
Various devices are known which enable such a turning over of the fillets.
Norwegian Patent 108 848 discloses a device in which a reversibly driven conveyor belt is used above which a further conveyor belt supplying the fillets ends, is provided the distance between the belts being smaller than the length of the fillets to be handled. In the end region of the first conveyor belt there is arranged a switching or controlling device which can be displaced by the fillets and makes the lower transport belt run in a counterdirection when activated and run in the same direction in the rest position. In this manner it is achieved that the fillets are turned with regard to their lateral and longitudinal directions.
Such known device does by no means cope with today's requirements regarding efficiency.
Furthermore, a device for crumbling foodstuffs is known from U.S. Pat. No. 3 860 105. This device comprises a region in which the crumbled foodstuff performs a somersault by being thrown from one conveyor onto another one arranged therebeneath. The aim of such action is to shake off any excess crumbs which may be present e.g. by way of aggregations in hollow spaces of such foodstuffs.
Also, there is disclosed by WO 89/07892 a turning device for fish fillets which are turned from a conveyance in the direction of their longitudinal axis to a direction transverse thereto and simultaneously from the skin side onto the meat side. This action occurs at the deflection or reversing point of a conveyor-belt conveying the fish fillets, which are thrown down onto a transverse slide or chute upon performance of a somersault, from which chute they are supplied to a second conveyor-belt which is arranged transverse to the first conveyor-belt.
Finally, there is disclosed in German OS (Published Patent Application) 38 38 154 a turning over and stretching device for fish fillets, in which device the turning over is performed by way of somersaulting which is imposed on the fish fillets through their transfer from one conveyor-belt to another one arranged below.
The principle of somersaulting has not proved a success in the practice of process performance on board of ships because a perfect function essentially depends, among other parameters, on a defined effectiveness of gravity, which prerequisite is not guaranteed in the case of even only slightly rough seas.